Method of drying gelatin



' HAWRY W LUJSGHER A TTORNEY.

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m: ,1 a a HARRY W. LUSCHERyQE GABROLI-JVILLE,-WISCONSIN, AS-SIGNGR TO UNITED STATES -GI|UE GOIMPANY, A CORPORATION OF WISCO1\TSIN.

iuE'rnon or DRYING GELATIN,

Application filed March so, 1922.; Serial No. s aori.

To all whom it may concern." w

Be it knownthat l, HARRY W. Luscnnn, a citizen of the United States, residing at arrollville, town of Oak-Creek, State of lVisconsin, have invented a certain new and useful Method of Drying Gelatin, of which the following is a specification.

In the manufacture of gelatin, particularly of that desired for edible and photographic purposes, it is important that Viscosity tests be as high as possiblevand that the low the product be as nearly sterile as possible. Gelatin forms a natural culture mediumfor the growth of bacteria and, it must be free from antiseptics or disinfectants of any kind, particularly if it is desired for usea's a food. p

In manufacturing gelatin-the raw -material from the liming is first. extracted at temperaturesvarying'from155 to 165 desix hours. his then evaporated under a vacuum of approximately 25 inches which causes it to boil in the neighborhood of 138 to 1&0 degrees Fahrenheit, and these temperatures being above Pasteurizingtem peratures result in what is then a practically sterile product. it thecompletion' of the gelatin is thereafter carefully done, referably in apparatusand pipes lined-wit glass so that it can not take-up any metal which it is very prone to do, it can lie-kept pure and sterile upto; the time out drying.

lit is customary to partially harden the" gelatin by, means oif spreading machines of the general type disclosed in Letters Patent" No. 1,309,995, issued to C. Bates under date ,of Jul 15, 1919, and then spread thepartially ardened gelatin on nets which are transferred to drying alleys. ere is practically no danger of contamination by bacteria in the spreading machine owing to temperatures used, but when the gelatin nets are spread in the drying alleys and subjected to a flow of heated air with temperatures varying from 85 to races: grees Fahrenheit, the danger of contamination is markedly increased.

Experience has determined that as the.

gelatin is drying on the nets in the, drying alley bacteria enter with the air and lodge on the surface of the gelatin. The num: bers and kinds of bacteria present, of course,

vary through quite Wide ranges dependingv upon the temperatures and relativehumidity, cold, dry air being" comparatively bacteria vfree, While moist, warmair is generally highly contaminated. I There may be,and'

does not kill the bacteria but merely causes them to lie dormant and they become active again when the gelatin is mixed with water and commence to propagate, with aresultant deleterious efiectupon the gelatin solution; This is particularly noticeable with organisms of the liqueiying type. lit is also true with many other kinds of organisms present. a 1

Experiments have indicated the inadvisability of, and Various pure food departments have precluded the use of, disinfectants which are dissolved in the gelatin it self such as are customarily used in the manufacture of glue, e. g., zinc sulphate, etc.-

Experiments have also shown that most gaseous disinfectants must .be used Very sparingly, if at all, as they arereadily ab:

sorbed by the gelatin rendering it insoluble,

and if present in any quantities'are really adulterants'. For example, it is possible through very careful manipulation to use chlorine gas or formaldehyde gas,but unless the quantities used-are carefully regulated and very minute, in the case of chlorine, for exam le, in the proportion of one part chlorine ac-100,000 parts of air, the excess chlorine is absorbed by the gelatin causing it to become insoluble in water and the resultant product. is therefore worthless, The same thing is true with formaldehyde gas and other so-called gaseous disinfectants.

l have discovered that substantially sterile gelatin may be made by conducting the drying in the drying alleys in the presence of ozone. ..'l.he nascent oxygen produced by the czonized aircxidizes the bacterialaden dust producing an antiseptic air, and the ozone is not absorbed by the gelatin and'it does not affect the qualitiesoi the gelatin whatsoever.- So tar as the gelatin itself is concerned the ozoni'zed air is inert but it exerts a powerful selective action on the dust particles, bacteria, etc, and therefore may he used in quantities without injury to the gelatin.

l' find that as a matter of economy it is advlsable to first remove the excess of dust bypassing the air through mechanical filr' tilt Nil

. This is not necessary ever, has not proven practicable.

I append drawings as a part of this specification showing one method of introducing ozone in actual practice.

%n the drawings,

i igure 1 represents the plan view of the alley with coils, and

Figure 2 is a being broken thereof.

In the drawings 1 represents the alley and 1 the neck thereof, 2 the spreading nets in position which is the fan driven by the motor 5 through gearing 6 or other suitable means, 7 are the heating coils for heating the air which is drawn through the filters8, which are made with a lip or ring- 9 which fits over the perforated plate 10 and are held at the bottom by a cord 11 fitting into an eyelet 12.

Part of the air, approximately 10 per cent, but the exact amount of which may vary, is taken from the chamber 18in which the filters 8 are located, through a by-pass 14,;into the ozonizing machine 15 and is then fan and ozone' machine;

side View of the alley, parts away to show the interior delivered through a by-pass 16 into the neck I of the alley l where it is commingled with the other air by on the suction side of the fan,

the turbulence created by the fan and forced in the direction of the arrows through the alley 1 and across the surface of the nets 2 and out at the discharge end of the alley. The ozonizing machine 15, together with the by-passes 14 and 16 are preferably located near the top ofthe neck of the alley l and are shown in the drawings as suspended on a platform 17 by hangers 18. p but has the advantage of getting the machine out of the way so that the o erator has room enough to walk underneat the platform 17 without striking his head in case it is desired to walk alongside of the alley.

When in operation the air is drawn in through the filters 8 into the chamber 10 by the suction of the fan 4. A portion thereof are held on the racks 3; 4:

goes through the by-pass 14 throughthe ozonizing machine 15 and returns to the neck of the alley 1 through the by-pass 16. The major portion of the flow is drawn through the heating coils 7 and the flows converge in front of the fan 4: and are then forced through the alley 1 and over the nets 2 and out of the discharge end. The turbulence of the fan is such that the ozonized air is completely mixed with the unozonized air and the rate of flow is such that suificient contact is made and time allowed between the time the ozonized air comes in through the by-pass 16 and the time the air strikes the first net 2 so that the air is completely sterilized.

As an indication of the remarkable effects that I have produced by the use of ozonized air, I have been enabled to reduce the bacteria content of liquefying organisms in gelatin from 8,000,000 per gram to 1,000 per gram and a reduction of a total bacteria count from 26,000,000 per gram to 380,000 per gram.

Tlge apparatus indicated in the drawings is, o variations in the method of applying the ozone.

eslre to cover as new and claim is: 4 1, The method of drying substantially sterile gelatin and preventing its contamination during drying, which consists in placing the gelatin in a drying compartment and subjecting it to the drying action of oz0nized air while in said compartment.

2. The method of drying substantially sterile gelatin and preventing its contamination during drying, which consists. in placing the gelatin in a drying compartment, filtering the drying air to remove excess foreign matter, heating a part of this drying air and passing another part of the drying air through an ozonizer, mixing the heated air with the ozonized air and subjecting the gelatin to the drying action of this mixture of heated. ozonized air while in said compartment.

HARRY WV. LUSCHER.

course, subject to obvious changes and Having fully described my invention what i 

